Steam trap



NGN. 17,1931. J, L FlTTs l.1,832,29*

- STEAM TRAP Filed Oct. 27, 1926 Wan/Pi; j

Patented Nov. 17, 1931' UNITED STATES PATENT OFFICE JAMES L. FITTS, .0F MERCHANTVILLE, NEW JERSEY, ASSIGNOR T0 WARREN WEBSTER & COMPANY, .A CORPORATION OF NEW JERSEY STEAM TRA? 'Application led October 27, 1926. Serial No. 144,448.

The object of my invention is to provide an efficient construction of condensation steam trap adapted to operate under high pressure for permitting the passage of water of con densation but restricting or preventing the passage of steam.

My improvement has a further object, namely, to provide a construction of the hollow therniostatic member or members, for use singly or in tandem within a suitable casing, and wherein the member is built up of flexible diaphragms and rigid annular portions mechanically connected by clamped soldered joints, to provide fiexibility from the hub portion to the perimeter and thereby secure the desired elasticity 'with a minimum diameter to the expansible member.

The invention has for a further object the obtainment of a large movement to the valve member from thermostatic elements of relatively small diameter adapted for use with steam at medium and high pressures, even to one hundred pounds, Iand corresponding temperature, approximately 328 F. Without danger of collapsing.

A still further object is to form the structure ofthe thermostatic member of metals capable of maintaining elasticity under high4 pressure and temperature and the port con trolling means of non-rustable alloy, such, for example, by use of sheet Monel metal (alloy of copper and nickel) for the iexible disks brass for the hub portions, and rustless steel (chrome iron alloy) for the seat and valve piece, whereby efiicient ope-ration and durability are assured.

With the foregoing and other objects hereinafter stated in view, my invention consists of certain improvements in steam traps fully described in the following specification and pointed out in the claims.

Referring to the drawings: Fig. -1 is a vertical section of a steam trap embodying my invention; Fig. 2 is an enlarged vertical section of my improved thermostatic structure removed froml its casing; Fig. 3 is a plan view of the thermostatic structure embodying my improvements when removed from its casing; Fig. 4 1s a cross section of the disk member of Fig. 3 taken on line 4-4 thereof;

Figs. 5 and 6 are cross sections of modifications; and Fig. 7 is a modification of the thermostatic member.

The present invention is an improvement upon the general type of trap described in Letters Patent of the United States N o. 1,235,618, granted to me on August 7, 1917, wherein the therinostatic disk members were formed of diaphragm disks of sheet metal having their perimeters united by an annular joint formed of a double folded seam occupying a large portion of the diameter and area of the disk. In the present invention, all interfolded seams are eliminated and an efficient simpler construction employed.

Referring to Fig. 1, :he body or casing 2 may be of any form desired but is shown of a form well suited to my improved thermostatic vapor expansion element, and is provided with aside inlet 3 and a bottom outlet 4, the latter having a valve seat preferably formed of rustless metal such as chromenickel iron alloy or chrome steel alloy, which eliiciently resists abrasion due to wire drawn condensation discharge. By employment of these rustless alloys, not only is the abrasion prevented owing to the non-rusting qualities of the same, but the smoothness of the valve seat is maintained and permits free discharge with a minimum opening by the thermostatically operated valve. The upper portionof the valve body is closed by a bonnet or cap 9 screwed thereon at 10 and providing access to the interior thereof for practically its entire area. 8 is a sheet metal disk having a diameter somewhat greater than the interior of the body so that its perimeter rests in an annular groove in the annular rim of the body, as shown in Fig. 1. interposed between the perimeter of-the disk S and the bonnet 9 is a ring washer preferably of the copper-asbestos gasket type, the same forming a steam tight joint over the junction of the disk perimeter and edge of the annular' depression as definitely shown at 2a in Fig. l.v The disk 8 is provided with a central hole and also with one oi' more holes 8a to permit equalization of pressure above and below the disk. The therinostatic vapor expansion element 7 is provided with a valve piece G at the bottom for controlling the thoroughfare or discharge opening through the seat 5 and has at the top an upwardly'extending threaded nipple 29 which extends through the central orifice in Athe disk 8 and is secured therein by clamping nut 80. In this manneygtiie thermostatic element is definitely supported and the distance between the said support and the discharge orifice positively assured, which facilitates greatly in the assembly.

Referring more particularly to the thermostatic element removed from the body or casing and, as illustrated, on an enlarged scale in Fig. 2, the following Jfeatures of construction are specially noted: As shown, the element 7 is composed of' two thermostatic disk members 7a and T connected together and having their respective expansion chambers 12, 12, in communication with each other and operating as a whole like a bellows type of expansion element. Then the disk members 7a and 7b are each constructed in the following manner, namely, a heavy annular ring like rim 15 of brass having two beaded outer edges 1G constitutes the perimeter of the expansible element and two flanged flexible disk shaped plates 13, oppositely flanged as at 141, are respectively placed over opposite sides of the ring like rim and 'rolled tightly over the respective bead like rim portions 16 and soldered rigidly in position as shown at 17, the solder being sweated in to insure a better union. This joint constitutes a'mechanical joint as the disks are, in ell'ect, hooked upon the bead like portions 16 and this mechanical joint isr strengthened and made tighter by the soldered union 17 between the disk members 13 and between them and the ring member 15. To-insure maximum fiexibility of the plates 13, they must not be attached to the top and bottom of the ring member 15 and to insure their freedom of movement, the top and bottom annular walls of the ring member 15 are beveled inwardly as at 18 to provide a clearance between said parts and the plates 13. In this way, the flexibility of the plates extend to the bead like portions 16 of the ring like members 15 and hence for their full diameters. The central portions of these disk like plates 13 are provided with apertures, preferably of the same diameter. there there are two expansible elements to be connected as shown and with their vapor chambers 12, 12, in communication, the joint is made by an interposed ring or Washer 20 through which and over the same and disk members 13 is placed a tubular part 21 which is then expanded and swaged down at 22, similar in function to the well known grommet used to fasten canvas or other substances together. The joint is then soldered at S to make it gas tight. In respeet to the hub 23 which carries the -valve cured to the uppermost disk member 13 ad-' jacent to its central opening is a hub 2o havingl its inner annular rim hanged or swaged as at 28 over a ring or washer 2T placed on the inner face of the disk plate 13, said construction being similar to that described in connection with the hub 22B and lowermost vdisk plate 13. Similarly, also this hub joint is.soldered as at S. As bel'ore pointed ont, this hub portion 26 is provided with the screw threaded nipple which extends through the central hole in the plate and clamped thereto by nut 30. It is pointed out. that where the parts 25 and 2S are formed as straight studs and are riveted over washers having straight holes, it has been impossible to 'make nonyielding joints and hence caused undesirable strains to come upon the soldered joints at S. By making the parts 2:3 and 2S annular and expanded and upset within a conical aperture in the nuts 24 and 2T. the metal portions ol the parts 25 and L-are disturbed 'throughout their mass and become set and tight, so thaty` no strain comes upon the soldered joints` and leakage of gas is thereby avoided. It will also be seen that a tapered charging hole ill extends through the hub piece 2b and by which air and a volatile fluid are admitted to the communicating expansion chambers 12, 12; said hole thereafter being sealed with a tapered plug and preferably soldered in position. The fluid to be volatilized may be alcohol or any other fluid adapted to be va-porized by steam heat, many of which are well known for use in thermostatic traps for steam heating systems.

In the making of the thermostatie element, the two middle disk plates 13 are united together at their central portions before their flanged perimeters 14 are secured to the beaded portions of the ring shaped rims 15. Further, the top and bottom plates 13 .are first secured to their respective hubs 26 and 23 and thereafter their flanged perimeters 14 are secured to the beaded portions of the ring shaped rims 15. This procedure enables all of the unions and joints to be easily made and gas' tight. The soldered joints S are sweated in so as to give the greatest security against vapor leakage and to strengthen the union as at the perimeter portions 17.

It will be understood that the thermostatic element may be formed in one or more of the expansible chambers 12, two such being shown Y the center hubs out to the curve .of the anged edges where they are united to the rim beads 16.

I have found that flatplates and those having annulacorrugations will in time assume a permanent bulged or arched form'which brings about a change in their elasticity and a change in the valve movement to and from the seat. To overcome this, I have provided a series of radial grooved or depressed portions located either upon the inside (Figs. 2 and 4) or outside (Fig. 5') of the disk surfaces or part outside and part inside (Fig. 6), said construction preventing to a very arge degree the objectionable bulging by throwing the flexure into that area near the outer edge, and yet by their form and shallow depth permit flexure more or less over the Whole plate area and elimination of sharp or eX- cessive bending at either center or outer portions. I have shown these radial portions at 19 in Figs. 2, 3, 4, 5 and 6.

While I have referred to the joints between the mechanically connected part being soldered at S, nevertheless, it is desirable that the surfaces shall be first tinned before assembled and the solder ap lied.

)Vhile I have shown in ig. 2 the two thermostatic elements 12, 12, with their interior' chambers in communication through the tubular union or part 21, it is to be understood that this communication is not essential because the several thermostatic elements may be made as indicated in Fig. 7 and the screw threaded hub 29 of one element may be screwed into the internally screw threaded hub 23, so that two or more of such elements may be coupled together with the uppermost screw threaded nipple 29 attached to the suspension plate or disk 8 while the valve piece 6 would be attached to the lowermost hub 23. In this arrangement, each one of the thermosult's, it is to be understood that I do not restrict myself to the details, as the same are susceptible of modification in various particulars without departing from the spirit or sco e of the invention.

aving now described my invention, what I claim and desire to secure by Letters Patent is:

1. A thermostatic expansive element having two fiexi'ble disk shaped walls of sheet metal whose perimeters are oppositely curved in the form of beads and said beaded perimeters spaced apart and out of contact, combined with an annular non-Hexible rim portion having its perimeter formed with parallel ribs semi-circular in cross section formed on the rim portions over which the curved perimeters of the sheet metal walls loosely extend but closely fit and by which they are self-locked in definitely spa-ced relation, and a soldered union between the separated beaded edges of the two fiexible Walls and the perimeter of the rim intermediate of its two semi-circular rib portions, the non-flexible rim forming the sealed perimeter of the expansive element.

2. The invention according to claim 1, wherein further, the flexible walls are provided with a large number of small radial ribs of substantially uniform depth, said ribs entirely separate from each other and beginning ad]acent to the nonlexible rim portion and terminating at a distance from the center to increase the resistance to bending in radial directions at substantially all points intermediate of the circumferential beginning and ending of the rib portions.

In testimony of which invention, I hereunto set my hand.

JAMES L. FITTS.

static elements would operate as separate ex- 

